Spoiled evaporator contents

[blissville maples]

So I pump my concentrate to the sugar House, there's usually 10 Gallons left in the line so I carry it up in a bucket and pour it in thru the steam away float box. At the end of the season last year I poured some in there the evaporator wasn't rip-roaring so maybe it didn't get sterilized enough because the next day when we went to boil we fired up like usual and all the sudden a slimy foam started coming out of the back pan windows. Luckily we had just fired and were able to shut down fairly quickly. Never seen or heard of this happening but everything in the pan had turned to slimy snot apparently overnight. it was like walking in egg whites, on the floor was a slimy stringy nasty mess from the over boil.

I'm wondering if if what I poured in didn't get sterilized enough and made the whole evaporator contents spoil, as I wouldn't think the concentrated flue pan sap would spoil overnight.

Any thoughts or similar experience?

[Russell Lampron]

The concentrate that you poured into the float box was probably full of bacteria and probably didn't get hot enough to kill it. That bacteria was enough to contaminate the rest of the contents in the steam away. Late in the season sap can turn to rope overnight. I had it happen to me one year after the last boil. The next day I started to drain the flue pan to finish it and it came out in strings and the concentrate in the flue pan was like jelly.

[maple flats]

Describe it again on what you did and when. As I read it I see "last year" and yesterday, Was last year a typo?

[wiam]

Describe it again on what you did and when. As I read it I see "last year" and yesterday, Was last year a typo?

Just curious why it would matter what year and I don’t see “yesterday”

[maple flats]

It sounded to me like the concentrate was added last year and now it is all spoiled, spanning 2 seasons makes a huge difference.

[n8hutch]

I think that you are right on about what caused your spoilage. I'm not sure what you could do differently other than just toss the 10 gallons down the drain next time. Must have had pretty near a barrel in the evaporator you lost.

Is it possible to pour it into the flu pan float box instead? 10 gallons is alot of cold/cool liquid.

[blissville maples]

"at the end of the season last year" - so what I had meant is this all occurred at the end of the season when my poly tanks had needed a good cleaning and the sap had alot of yeastiness to it. I kind of wondered if that may have potentially had something to do with it or the temps as it was april. I had done this same thing all season long so...... something was obviously different this time

Perhaps I should have done it half HR prior when the evaporator was boiling more and not being shut down??

N8hutch- yes your right I lost more than that 10 gals was worth!! And a huge hassle to boot, n2m and thank God we weren't rip roaring there was a tiny dark spot in bottom of couple flues since all liquid raised up in foam...

[Russell Lampron]

"at the end of the season last year" - so what I had meant is this all occurred at the end of the season when my poly tanks had needed a good cleaning and the sap had alot of yeastiness to it. I kind of wondered if that may have potentially had something to do with it or the temps as it was april. I had done this same thing all season long so...... something was obviously different this time

Perhaps I should have done it half HR prior when the evaporator was boiling more and not being shut down??

N8hutch- yes your right I lost more than that 10 gals was worth!! And a huge hassle to boot, n2m and thank God we weren't rip roaring there was a tiny dark spot in bottom of couple flues since all liquid raised up in foam...

Do you flush the sugar out of your RO when you're done concentrating? When I'm done I concentrate with permeate until I have less than 1% sugar in the concentrate. At that point the pipe to the head tank has less sugar than raw sap. What I drain back, which isn't much, goes down the drain.

[blissville maples]

Do you flush the sugar out of your RO when you're done concentrating? When I'm done I concentrate with permeate until I have less than 1% sugar in the concentrate. At that point the pipe to the head tank has less sugar than raw sap. What I drain back, which isn't much, goes down the drain.

I do also, and would think being less than a few percent sugar would be less chance of spoilage. I guess the 10 gals of 3 percent or whatever it is should go back in sap tank or on ground....

I'm wondering how much bacteria, even thoughthe last little bit of concentrate has been flushed and the sugar is only a couple to a few percent, is in the membranes. And can this bacteria just be pushed thru and picked up by the concentrate.
I feel like a membrane is nothing more than a huge hotel for bacteria!!

Either way it was a learning experience I will not forget!

[maple flats]

What I have done for years near the end of a boil is I watch my level gauge for my head tank. When it gets to 18 gal (I marked it at 6, 12 and 18 dumping water in the empty tank, my higher marks are guesses. Anyways, when my head tank gets down to 18 (for my 3x8 rig) I dump the rest in the pans and fire it 1 last time. It boils hard in a few minutes and boils for about 10 minutes before it starts to slow down. Doing that I have never lost a batch. Your numbers might be different based on your boil and size but it can be figured to boil the last added hard enough to kill any micro organisms or yeast. My head tank when I dump it likely has about 5-10% sugar, I never tested it at that point. I concentrate it to about 12% but then when the RO is done processing sap, I run a cold permeate rinse thru and into the head tank for 5-6 minutes. Depending on the head tank level at that time it may be reduced to the 5-10% or so.
The main thing is to make sure you get a few minutes of hard rolling boil after the last concentrate hits the pans, but on the flip side don't boil down too low. My cool down takes about an hour to get the hot coals all consumed, then I am usually about 12-1" above my usual boil depth. I cover my front pan and all 3 float boxes and leave. When I return the next day the level is usually 1/4-1/2" below my usual boil depth. Then I start all over.
On my raised flue evaporator my usual boil depths are 1" in the syrup pan and 1/2" over the flues in the back pan.